Alasdair Sandford

There is a long way to go before the French presidential election – but voters in France on Sunday could be helping elect the next occupant of the Elysée Palace.

The winner of the two-leg primary from the conservative party “Les Républicains” will have a good chance of going all the way to the presidential run-off next spring.

After the shocks of the UK’s “Brexit” vote to leave the European Union, and Donald Trump’s election as US president, the French race is increasingly being seen as another potential showdown between a weakened mainstream, and an insurgent populist force.

François Fillon voted early. The dark horse in the race is tagged as an economic liberal, even a Thatcherite – but he says he is just a pragmatist.

The former prime minister wants to do away with the 35-hour week and slash the size of government.

A better-known face internationally, former president Nicolas Sarkozy is seeking a second term. Against a backdrop of terror attacks on home soil and Europe’s migrant crisis, he has warned there is a threat to French national identity and unity – in what has been seen as a bid for the far-right vote.

Once the favourite but seen as under increasing pressure from his rivals, Alain Juppé – another ex-prime minister – argues that Sarkozy’s rhetoric will deepen not heal divisions.

The 71-year-old said he was feeling “zen” as he voted at just after 11 o’clock on Sunday morning.

He has talked of the need for “far-reaching and radical reform”, but he is struggling to arouse passions.

The first round will whittle down a field of seven to a run-off of two next weekend – assuming that no candidate polls more than 50 percent in the first round.

In the first centre-right primary of its kind, anyone who pays two euros and signs a pledge of allegiance to the party’s values can vote.

Much could change, but with the left in disarray the winner has been tipped to face Marine Le Pen of the anti-establishment Front National in the presidential run-off.

Given the traditional outsider’s wish to take France out of the European Union and the euro, the outcome of the French election could determine the future of the EU itself.